JP2020028132A - Terminal structure of superconducting apparatus - Google Patents

Abstract

To provide a terminal structure of a superconducting apparatus which is small-sized and also improves workability.SOLUTION: A terminal structure of a superconducting apparatus comprises a normally-conductive conductor extraction part electrically connected with the end of a superconductor of the superconducting apparatus. The conductor extraction part comprises a cylindrical part, a superconducting side connection part having a housing part housing the end of the superconductor while encapsulating one end side in the axial direction of the cylindrical part, and a normally-conductive side connection part being a metal fitting connected with a normally-conductive apparatus while encapsulating the other end side in the axial direction of the cylindrical part, and furthermore, comprises a non-vacuum heat-insulating material which covers an outer peripheral surface in the radial direction of the cylindrical part.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a terminal structure of a superconducting device.

  There is a superconducting cable as one of the superconducting devices. The superconducting cable is expected as an energy-saving technology because it can transmit a large amount of power with low loss while being small. The superconducting cable has a cable core having a superconducting conductor layer formed by spirally winding a superconducting wire around the outer periphery of a former, and a refrigerant (for example, liquid nitrogen) that houses the cable core and maintains the superconducting conductor layer in a superconducting state. And a heat-insulating tube filled with water.

  Patent Literature 1 discloses a superconducting device (superconducting device) in which a lead portion made of a normal conducting material is interposed between a superconducting conductor of a superconducting cable, which is one of superconducting devices, and a conductor of a normal conducting cable used at normal temperature. Cable) is disclosed. In this terminal structure, a rod-shaped normal conducting lead portion connected to the cable core of the superconducting cable, a rod-shaped conductor lead portion whose tip is arranged in a normal temperature environment, a room temperature side vacuum layer covering the outer periphery of both the lead portions, and a terminal. A vacuum layer.

JP 2015-192552 A

  In the conventional terminal structure of a superconducting device, since a plurality of vacuum layers for heat insulation are formed at the position of the lead-out portion, the terminal structure is complicated and easily enlarged. Depending on the construction space, it may be difficult to construct such a large terminal structure, and miniaturization of the terminal structure is desired.

  Further, since the process of forming a plurality of vacuum layers is complicated, there is a problem that the workability of the conventional terminal structure of the superconducting device is not good.

  Therefore, an object of the present disclosure is to provide a terminal structure of a superconducting device which is small and has excellent workability.

The terminal structure of the superconducting device of the present disclosure is:
A terminal structure of a superconducting device including a normal-conduction conductor lead-out portion electrically connected to an end of a superconducting conductor of the superconducting device,
The conductor lead-out portion,
A tubular portion,
A superconducting-side connecting portion that seals one end side of the cylindrical portion in the axial direction and has a storage portion that stores an end of the superconducting conductor,
Along with sealing the other end of the cylindrical portion in the axial direction, a normal-conducting-side connection portion serving as a bracket connected to a normal-conduction device,
Further, a non-vacuum heat insulator is provided to cover a radially outer peripheral surface of the cylindrical portion.

  The terminal structure of the above-described superconducting device is small and has excellent workability.

FIG. 2 is a schematic vertical sectional view of a terminal structure of the superconducting device according to the first embodiment. FIG. 2 is a partially enlarged view in the vicinity of a conductor lead-out portion of FIG. It is a schematic longitudinal cross-sectional view of a conductor lead-out part. It is a sectional perspective view of the superconducting cable with which the terminal structure of the superconducting device of Embodiment 1 is provided. It is the elements on larger scale near the conductor lead-out part in the terminal structure of the superconducting device of Embodiment 2.

-Description of embodiments of the present disclosure First, embodiments of the present disclosure will be listed and described.

<1> The terminal structure of the superconducting device according to the embodiment is as follows.
A terminal structure of a superconducting device including a normal-conduction conductor lead-out portion electrically connected to an end of a superconducting conductor of the superconducting device,
The conductor lead-out portion,
A tubular portion,
A superconducting-side connecting portion that seals one end side of the cylindrical portion in the axial direction and has a storage portion that stores an end of the superconducting conductor,
Along with sealing the other end of the cylindrical portion in the axial direction, a normal-conducting-side connection portion serving as a bracket connected to a normal-conduction device,
Further, a non-vacuum heat insulator is provided to cover a radially outer peripheral surface of the cylindrical portion.

  In the above configuration, by forming a cylindrical portion having a hollow inside and hardly conducting heat, a superconducting portion is formed between the normal conducting side connecting portion arranged at room temperature and the superconducting side connecting portion arranged at cryogenic temperature. Heat intrusion into equipment can be suppressed. Since the cylindrical portion is difficult to conduct heat, a non-vacuum heat insulating structure (non-vacuum heat insulator) having a simpler structure than the vacuum heat insulating structure can be adopted as the heat insulating structure for insulating the cylindrical portion from the external environment. . Since a non-vacuum heat insulator having a simple structure is small and can be easily installed, the terminal structure of a superconducting device including the non-vacuum heat insulator is small and has excellent workability.

<2> As one mode of the terminal structure of the superconducting device according to the embodiment,
The non-vacuum heat insulator may include a case including a case surrounding a radially outer side of the cylindrical portion, and a resin filled in the case.

  According to the above configuration, even when a complicated-shaped configuration such as a vacuum port is arranged on the outer periphery of the cylindrical portion or in the vicinity thereof, the non-vacuum heat insulator can be arranged on the outer periphery of the cylindrical portion without gaps. As a result, the transfer of heat from the external environment to the tubular portion can be effectively suppressed, and heat intrusion into the superconducting device can be suppressed.

<3> As one mode of a terminal structure of a superconducting device according to an embodiment including a non-vacuum heat insulator filled with a resin in a case,
The cylindrical portion includes a through hole penetrating the inside and outside thereof,
A mode in which the resin is also filled in the inside of the cylindrical portion through the through hole can be given.

  By forming a through-hole in the tubular portion and filling the inside of the tubular portion with a resin, it is possible to suppress the air from remaining inside the tubular portion. If there is residual air, the gas in the cylindrical part may repeatedly evaporate and liquefy, in which case the pressure fluctuations in the cylindrical part will apply stress to the surrounding members of the cylindrical part, and these members will degrade Might be. Filling the cylindrical portion with resin can suppress such a problem from occurring.

<4> As one mode of the terminal structure of the superconducting device according to the embodiment,
A mode in which a refrigerant distribution mechanism that distributes a refrigerant inside the cylindrical portion may be included.

  By cooling the tubular portion by the coolant circulation mechanism, heat generated in the normal-conducting-side connection portion and the tubular portion during load can be removed, and it is easy to suppress an increase in the temperature of the superconducting device. Here, in the terminal structure of the superconducting device according to the embodiment, since the heat insulating structure covering the outer periphery of the cylindrical portion is a non-vacuum heat insulator, it is easy to arrange the refrigerant introduction pipe, the refrigerant discharge pipe, and the like that constitute the refrigerant distribution mechanism. .

<5> As one mode of the terminal structure of the superconducting device according to the embodiment,
The superconducting device may be in the form of a superconducting cable including a cable core having the superconducting conductor and a heat-insulating tube for accommodating the cable core.

  According to the terminal structure of the superconducting device in which the superconducting device is a superconducting cable, it is possible to improve the workability of the power transmission network constructed with the superconducting cable. When the scale of the power transmission network is increased, the number of terminal structures of the superconducting equipment becomes very large. Therefore, by improving the workability of each terminal structure, the workability of the entire power transmission network can be significantly improved.

<6> As one mode of the terminal structure of the superconducting device according to the embodiment in which the superconducting device is a superconducting cable,
An insulating tube through which a part of the cable core is inserted,
A normal-conduction-side heat-insulating container that is arranged on the side of the conductor lead-out portion of the insulating cylinder and houses the normal-conduction-side connection portion together with an end of the cable core,
A superconducting-side heat-insulating container arranged on the side of the superconducting cable in the insulating cylinder and connected to the heat-insulating pipe of the superconducting cable.

  According to the above configuration, the normal-conduction-side connection portion of the conductor lead-out portion is double-insulated by the normal-conduction-side heat-insulating container and the non-vacuum heat insulator. Therefore, it is easy to suppress heat intrusion from the external environment into the cable core.

-Details of embodiment of the present disclosure Specific examples of the embodiment of the present disclosure will be described below with reference to the drawings. In the drawings, the same reference sign means the same name. It should be noted that the present invention is not limited to these exemplifications, but is indicated by the appended claims, and is intended to include all modifications within the scope and meaning equivalent to the appended claims. For example, the present invention can be applied to a multi-core collective cable.

<First embodiment>
In this example, a terminal structure 1 of a superconducting device that connects the superconducting cable 100 shown in FIG. 1 to a normal conducting device will be described as a terminal structure of the superconducting device. The terminal structure 1 includes a conductor lead-out portion 2 that electrically connects a superconducting conductor layer 112 provided in a cable core 110 of the superconducting cable 100 and a normal conductor (for example, a bus bar 200) of a normal device. Examples of the normal conducting device include a normal conducting cable such as an overhead power transmission line. One of the features of the terminal structure 1 of the superconducting device is the configuration of a conductor lead-out portion 2 and a heat insulating structure (a non-vacuum heat insulator 3 described later) that insulates a portion of the conductor lead-out portion 2 on the superconducting device side from the external environment. Can be mentioned. In this example, the portion of the conductor lead-out portion 2 that is exposed to the normal temperature environment from the non-vacuum heat insulator 3 and the bus bar 200 are fastened with bolts 200b to electrically connect the superconducting cable 100 and the normal conducting device. are doing. Hereinafter, first, the basic configuration of the superconducting cable 100 will be described with reference to FIG. 4, and then the detailed configuration of the terminal structure 1 of the superconducting device for connecting the superconducting cable 100 to the normal conducting device and the construction procedure will be described. .

≪Superconducting cable≫
The superconducting cable 100 includes a cable core 110 having a superconducting conductor layer (superconducting conductor) 112 provided on the outer periphery of the former 111, and a heat insulating tube 120 for housing the cable core 110. The cable core 110 shown in this example includes a former 111, a superconducting conductor layer 112, an electric insulating layer 113, a shielding layer 114, and a protective layer 115 coaxially from the center. This superconducting cable 100 is a single-core cable in which one cable core 110 is housed in one heat insulating tube 120, and an electric insulating layer 113 is housed in a heat insulating tube 120 together with a superconducting conductor layer 112, and both are made of refrigerant. It is a low-temperature insulated cable cooled by. For example, three such single-core cables are laid, and a three-phase AC power transmission line using each cable for power transmission in each phase, or two such single-core cables are laid, and one cable is forwarded. In addition, it is possible to construct a DC power transmission path using the other cable for the return path.

[Former]
The former 111 has a function of supporting the superconducting conductor layer 112. In this example, the former 111 is a hollow body so as to be used also for the flow path of the refrigerant 130 such as liquid nitrogen. As a constituent material of such a former 111, a metal such as stainless steel which can be used even at a refrigerant temperature and has excellent strength even when it is thin. When a corrugated pipe or a bellows pipe is used for the former 111, flexibility is excellent even if it is made of a high-strength material. Unlike the present example, the former 111 may be a solid body such as a stranded wire obtained by twisting a plurality of element wires (a copper wire, a coated copper wire having an insulating coating such as an enamel around the copper wire). it can.

[Superconducting conductor layer]
The superconducting conductor layer 112 is formed by spirally winding a plurality of superconducting wires around the outer periphery of the former 111. As the superconducting wire, for example, a tape-shaped wire such as a Bi-based silver sheath wire or a RE123-based thin film wire can be used. The number of wires and the number of wire layers may be appropriately selected so as to have a desired current capacity. FIG. 1 shows a case where the superconducting conductor layer 112 is formed by laminating four wire layers. An interlayer insulating layer (not shown) wound with insulating paper or the like may be provided between the wire rod layers. An intervening layer (not shown) may be provided between the former 111 and the superconducting conductor layer 112 for the purpose of mechanically protecting the superconducting conductor layer 112 and the like.

[Electrical insulation layer]
The electrical insulating layer 113 ensures electrical insulation between the superconducting conductor layer 112 and the outside. The electric insulating layer 113 is formed by spirally winding a tape made of an insulating material around the outer periphery of the superconducting conductor layer 112. Examples of the insulating material include kraft paper and insulating paper such as semi-synthetic paper such as PPLP (registered trademark; Polypropylene Laminated Paper).

[Shielding layer]
The shielding layer 114 is provided on the outer periphery of the superconducting conductor layer 112 (in this example, immediately above the electric insulating layer 113), and shields an electric field caused by the superconducting conductor layer 112. The shielding layer 114 is formed by winding a tape or a wire made of the above-described normal conductive material such as a copper tape.

[Protective layer]
The protective layer 115 is disposed on the outermost periphery of the cable core 110, and mechanically protects a member (particularly, the superconducting conductor layer 112) disposed inside the cable core 110, and secures electrical insulation between the shielding layer 114 and the heat insulating tube 120. It is provided for the purpose. Such a protective layer 115 is formed by spirally winding the above-described insulating paper around the outer periphery of the shielding layer 114.

  In addition, the cable core 110 may include an outer superconducting layer (not shown) on the outer periphery of the electric insulating layer 113 and a magnetic shielding layer made of a normal conducting material. The outer superconducting layer is formed by spirally winding the above-described superconducting wire. The outer superconducting layer, for example, can be used as a magnetic shielding layer in AC power transmission applications, and in a DC power transmission application, in the case of monopole power transmission, can be used as the return conductor when the superconducting conductor layer 112 is used as the outward conductor, and in the case of bipole power transmission. It can be used as a conductor for flowing a current having a polarity opposite to that of the superconducting conductor layer 112.

[Insulated tube]
The heat insulating tube 120 is a double-structured tube having an inner tube 121 and an outer tube 122, and the space between the inner tube 121 and the outer tube 122 is evacuated, and a vacuum heat insulating layer is formed in this space. Insulated pipe. The internal space of the inner tube 121 is a storage space for the cable core 110 and is used for a flow path through which a refrigerant (for example, liquid nitrogen or the like) for maintaining the superconducting state of the superconducting conductor layer 112 flows. The inner pipe 121 and the outer pipe 122 can be formed of a corrugated pipe or a bellows pipe having excellent flexibility, or a straight pipe capable of reducing the pressure loss of the refrigerant. The constituent material of the inner tube 121 and the outer tube 122 includes a metal such as stainless steel. The heat insulating pipe 120 shown in this example is provided with a heat insulating material 123 such as super insulation (trade name) between the inner pipe 121 and the outer pipe 122. An anticorrosion layer 124 made of an anticorrosion material such as vinyl or polyethylene is provided outside the outer tube 122 of the heat insulating tube 120.

端末 Terminal structure of superconducting equipment≫
When connecting the above-described superconducting cable 100 and a normal conducting device, for example, the terminal structure 1 of the superconducting device shown in FIG. The terminal structure 1 in FIG. 1 is a horizontal type in which the conductor extraction portions 2 are drawn out in the horizontal direction indicated by arrows at both ends, but may be a vertical type in which the conductor extraction portions 2 are drawn vertically upward. The left side of the arrow is the normal conduction side (normal temperature side), and the right side is the superconducting cable 100 side (cryogenic side).

  In the terminal structure 1, the end of the cable core 110 exposed from the heat insulating pipe 120 is electrically connected to the conductor lead-out portion 2, and the conductor lead-out portion 2 is further connected to a normal conductor (normally a bus bar 200 in this example) of a normal conduction device. ). Further, in the terminal structure 1, the insulator tube 7 is arranged on the outer periphery of the cable core 110, and a vacuum refrigerant tank (a normal-conduction-side heat-insulated container 5 and a superconducting-side heat-insulated container 6, which will be described later) extends from the exposed portion to the end of the cable core 110. Is provided. The refrigerant 130 that cools the cable core 110 is introduced into the refrigerant tank 61 of the superconducting heat-insulated container 6 via a refrigerant introduction pipe 11 provided in the superconducting heat-insulated container 6 described below. The refrigerant 130 introduced into the refrigerant tank 61 passes through the refrigerant tank 51 of the normal-conduction-side heat-insulating container 5 and is positioned at the end of the superconducting cable 100 on the conductor lead-out part 2 side, as indicated by the outline arrow in FIG. Is introduced into the hollow hole of the former 111. The refrigerant 130 introduced into the former 111 is discharged into the inner pipe 121 of the cable core 110 at an appropriate position, passes through the outside of the cable core 110, and passes through the refrigerant discharge pipe 19 provided in the superconducting heat insulating container 6. Is discharged outside. A refrigerator is disposed outside, and the refrigerant 130 cooled by the refrigerator is sent into the terminal structure 1 again through the refrigerant introduction pipe 11. Note that the flow direction of the refrigerant 130 may be opposite to the above-described example. That is, the refrigerant 130 may be introduced from the refrigerant discharge pipe 19 and the refrigerant 130 may be discharged from the refrigerant introduction pipe 11.

[Cable core]
In the cable core 110 protruding from the end of the heat insulating tube 120 (see the vicinity of the vacuum port 100p), the shielding layer 114 and the protective layer 115 (FIG. 4) are cut near the heat insulating tube 120. In a region of the cable core 110 that is ahead of the opening of the heat insulating tube 120, the electric insulating layer 113 is generally exposed. Further, the tip of the cable core 110 (the portion protruding from the room temperature side end of the insulating cylinder 4) is stripped off, and the former 111 and the superconducting conductor layer 112 are exposed in order from the tip.

  The exposed superconducting conductor layer 112 and the conductor lead-out portion 2 are joined by an appropriate joining material such as solder or brazing material, and both are electrically connected. The conductor lead-out section 2 of this example has a storage section 21s (see FIGS. 2 and 3) into which one end of the cable core 110 is inserted, and the storage section 21s has an end section of the cable core 110. Is inserted, and the superconducting conductor layer 112 is fixed in the storage section 21s by the bonding material. In this example, the former 111 is further connected to the conductor lead-out portion 2 by a fastening member such as a bolt penetrating through the fastening hole 21p. As a result, the connection strength between the cable core 110 and the conductor lead portion 2 is increased. An injection hole 21h (FIG. 3) for a bonding material is formed in the storage portion 21s of the conductor lead-out portion 2.

  On the other hand, in the cable core 110 drawn out of the heat insulating pipe 120, the area opposite to the above-mentioned tip end, that is, near the end of the heat insulating pipe 120, the shielding layer 114 and the protective layer 115 were removed and exposed. The region (cable-side region) includes a reinforcing insulating layer 8 provided on the outer periphery thereof. The reinforcing insulating layer 8 is formed by spirally winding insulating paper around the outer periphery of the cable core 110 (here, the electric insulating layer 113). The reinforcing insulating layer 8 has a shape that tapers from a central portion in the longitudinal direction (the left-right direction in FIG. 1) toward each end, that is, a shape that tapers toward the room temperature side and the cable side. Each inclined portion functions as a stress cone. The shield connection portion 80 is formed from the shield layer 114 (FIG. 4) of the cable core 110 to the stress cone portion on the cable side in the reinforcing insulating layer 8. The shield connection part 80 is formed by winding a wire made of a normal conductive material such as copper.

[Insulating tube]
The insulating cylinder 4 is provided on the outer periphery of an intermediate portion between the distal end portion in the extending direction of the cable core 110 and the portion where the reinforcing insulating layer 8 is provided. The insulating cylinder 4 is a member that performs electric insulation between the cable core 110 and the outside and also alleviates an electric field. On the outer periphery of the insulating tube 4, a fixing portion 40 fixed to the insulator tube 7 described later is provided.

  A part of the insulating cylinder 4 shown in this example comes into contact with the refrigerant 130. Therefore, the constituent material of the insulating cylinder 4 is preferably an insulating material that can be used without any problem even at the refrigerant temperature. Excellent. The normal temperature side region of the insulating cylinder 4 arranged in the insulator tube 7 has a tapered shape toward the normal temperature side, and the tapered inclined portion functions as a stress cone. By providing a metal foil (not shown) concentrically in multiple layers in the insulating cylinder 4, the electric field can be adjusted. On the other hand, the outer peripheral surface of the cable side region of the insulating cylinder 4 is a uniform cylindrical surface, but its inner peripheral surface is inclined radially inward toward the room temperature side. With this inner inclined surface, a space between the reinforcing insulating layer 8 and the insulating cylinder 4 can be secured.

  The fixing portion 40 is joined to the outer periphery of the insulating cylinder 4 (in this example, a central portion in the longitudinal direction, not a stress cone portion). The fixing portion 40 includes a flange portion extending outward from the insulating cylinder 4. The insulating tube 4 can be fixed to the insulator tube 7 by fastening the flange portion to the insulator tube 7 with a bolt or the like. As a constituent material of the fixing portion 40, an appropriate metal, resin, or the like is used.

[Superconducting side heat insulation container]
The superconducting-side heat-insulating container 6 is a heat-insulating tank arranged on the side of the superconducting cable 100 in the insulating tube 4 and connected to the heat-insulating pipe 120 of the superconducting cable 100. The superconducting-side heat-insulating container 6 is composed of a refrigerant tank 61 and a vacuum tank 62 covering the outer periphery thereof, and the space between both tanks 61 and 62 is evacuated. A heat insulating material such as super insulation (trade name) may be arranged between the two tanks 61 and 62. The refrigerant 130 can be maintained at an extremely low temperature by the vacuum space formed in the superconducting-side heat insulating container 6.

  The superconducting-side heat-insulating container 6 is provided from the end of the heat-insulating tube 120 to the bottom plate portion 71 of the insulating tube 7. A part of the outer periphery of the cable core 110 and the outer periphery of the cable-side region of the insulating tube 4 are provided therebetween. cover. The refrigerant tank 61 is connected to the inner pipe 121 of the heat insulating pipe 120, and the vacuum tank 62 is connected to the outer pipe 122 of the heat insulating pipe 120. Since the outer pipe 122 is at the ground potential, the vacuum tank 62 is also connected to the ground potential. Has become. The inside of the refrigerant tank 61 is partitioned between the refrigerant introduction pipe 11 and the refrigerant discharge pipe 19 in the longitudinal direction of the superconducting cable 100, and the refrigerant 130 introduced from the refrigerant introduction pipe 11 is immediately discharged from the refrigerant discharge pipe 19. Not to be.

  It is preferable to provide a stress relaxation structure (not shown) in the superconducting heat insulating container 6. As the stress relieving structure, for example, a part of the refrigerant tank 61 in the axial direction may have a bellows structure.

[Normal conduction side heat insulation container]
The normal-conduction-side heat-insulating container 5 is a heat-insulation tank that is arranged on the normal-conduction side of the insulating tube 4 and stores the tip of the superconducting cable 100 therein. The normal-conduction-side heat-insulating container 5 includes a refrigerant tank 51 and a vacuum tank 52 covering the outer periphery thereof, and the space between the tanks 51 and 52 is evacuated. A heat insulating material such as super insulation (trade name) may be arranged between the two tanks 51 and 52. In this example, the vacuum space of the normal-conduction-side heat-insulating container 5 and the vacuum space of the superconducting-side heat-insulating container 6 are provided so as to overlap in the longitudinal direction of the cable core 110 via the insulating tube 4.

  The normal-conduction-side heat-insulating container 5 is provided so as to extend from the inside of the insulating tube 4 to the room-temperature side via the inside of the insulator tube 7. In this example, the refrigerant tank 51 of the normal-conduction-side heat-insulating container 5 is connected to the conductor lead-out unit 2, and the vacuum tank 52 is connected to the upper plate 72 of the insulator tube 7. An end of the normal-conduction-side heat-insulating container 5 on the conductor lead-out portion 2 side protrudes from the insulator tube 7.

  The coolant tank 51 is filled with a coolant 130 for cooling the cable core 110 (particularly, the superconducting conductor layer 112) inserted through the inner periphery thereof, and is used for a flow path, and forms a vacuum space with the vacuum tank 52. The above-described insulating cylinder 4 is integrally provided on the outer peripheral surface of the vacuum tank 52 that covers the outer periphery of the refrigerant tank 51. The normal-conduction-side heat-insulating container 5 including the refrigerant tank 51 and the vacuum tank 52 is in contact with the conductor lead-out portion 2 and has a high potential. The insulating vessel 4 integrated with the vacuum tank 52 of the normal-conduction-side heat-insulating container 5 is insulated from the normal-conduction-side heat-insulating container 5 having a high potential and the superconducting-side heat-insulating container 6 having a ground potential.

[Insulator tube]
The insulator tube 7 accommodates the room temperature side region of the insulating cylinder 4 and is used for electrical insulation between the superconducting conductor layer 112 inserted into the insulating cylinder 4 and the outside. The insulator tube 7 of this example includes a cylindrical main body 70 having an insulator series, an annular bottom plate 71 provided at one end (an end on the superconducting side) of the main body 70, and the other end (normal electric conduction) of the main body 70. And an annular upper plate 72 provided on the (side) side. The fixing part 40 of the insulating cylinder 4 is attached to the bottom plate part 71. The outer periphery of the normal-conduction-side heat-insulating container 5 is fixed to the upper plate portion 72, so that a part of the normal-conduction-side heat-insulation container 5 protrudes from the insulator tube 7. The enclosed space (the internal space of the insulator tube 7) surrounded by the main body 70, the bottom plate 71, and the upper plate 72 is filled with an insulating oil (not shown) such as insulating oil or SF6. The main body 70 is provided with an inlet / outlet pipe (not shown) for an insulating fluid. Lines of electric force extending from the inclined surface on the normal temperature side of the insulating cylinder 4 are drawn out from the region of the insulator series. An upper shield 75 is provided at an end on the normal conduction side of the porcelain tube 7 and on an outer periphery of a case 30 described later.

[Conductor lead-out part]
The conductor lead-out portion 2 is a member that is electrically connected to the end of the superconducting conductor layer 112 exposed at the end of the above-described cable core 110, and includes a normal conducting material such as copper, an alloy thereof, aluminum or an alloy thereof. It is composed of materials. FIG. 3 is mainly referred to in describing the conductor lead-out portion 2. FIG. 3 is a longitudinal sectional view of the conductor lead-out portion 2 of FIGS.

  As shown in FIG. 3, the conductor lead portion 2 of this example is formed by joining a tubular portion 20, a superconducting-side connecting portion 21, and a normal-conducting-side connecting portion 22. The superconducting-side connecting portion 21 seals an opening at one axial end of the cylindrical portion 20 (on the right side of the arrow and on the superconducting cable 100 side), and the normal-conducting-side connecting portion 22 extends in the axial direction of the cylindrical portion 20. Is sealed at the other end. These three members are connected by solder, bolts, or the like.

[[Cylindrical part]]
The tubular portion 20 is a member for reducing the amount of heat that enters the superconducting side connecting portion 21 from the normal conducting side connecting portion 22. In the AC power transmission, the effective cross-sectional area of the tubular portion 20 as a conductor is not reduced by the influence of the skin effect. The shape of the tubular portion 20 is not limited as long as it is formed in a tubular shape. The cylindrical portion 20 of the present example is a cylindrical member whose inner and outer diameters are uniform. The inner and outer diameters of the tubular portion 20 may be determined according to the amount of current exchanged between the superconducting cable 100 and the normal conducting device. That is, the inner diameter and the outer diameter of the cylindrical portion 20 are determined so that a sufficient conductor cross-sectional area for the exchange of the current amount can be secured.

  The outer peripheral surface of the cylindrical portion 20 is provided with a through hole 20h penetrating the inside and outside of the cylindrical portion 20. The through hole 20h is a passage for a resin 32 (FIGS. 1 and 2) described later. It is preferable to provide a plurality of through holes 20h in order to improve the filling property of the resin 32. In particular, it is preferable to provide a plurality of through holes 20h evenly in the circumferential direction of the cylindrical portion 20. The through-hole 20h also functions as a breathing hole for releasing the air inside the cylindrical portion 20 expanded by the heat of the solder to the outside when joining the end of the superconducting cable 100 to the conductor lead-out portion 2 with solder. Have.

[[Superconducting side connection]]
The superconducting-side connecting portion 21 is a member in which a bottomed cylindrical sealing tubular portion 21A and a main body portion 21B extending from the outer bottom of the sealing tubular portion 21A are integrated, and is directly connected to the superconducting cable 100. . The inner diameter of the sealing tubular portion 21A is slightly larger (about 0.5 mm to 2 mm) than the outer diameter of the tubular portion 20. Therefore, by fitting the sealing tubular portion 21A to one end of the tubular portion 20 in the axial direction, one end of the tubular portion 20 in the axial direction can be sealed. The joining between the tubular portion 20 and the sealing tubular portion 21A can be performed with solder or the like.

  The main body portion 21B includes a housing portion 21s at one end portion for housing the distal end portion of the cable core 110 (in this example, the former 111 and the superconducting conductor layer 112). On the inner bottom side surface of the storage section 21s, a refrigerant flow path 21c extending from the internal space of the storage section 21s to the outside in the radial direction of the storage section 21s is formed. As shown in FIG. 2, the hollow hole of the former 111 inserted into the storage section 21s communicates with the refrigerant flow path 21c, and the refrigerant 130 discharged from the hollow hole passes through the refrigerant flow path 21c and is connected to the normal conduction path. It is discharged into the refrigerant tank 51 of the side heat insulating container 5.

  The inner diameter of the storage portion 21s is reduced stepwise in order from the superconducting cable 100 (FIG. 1) side. The former 111 is disposed on the inner peripheral surface with the smallest inner diameter in the storage portion 21s, and each layer of the superconducting conductor layer 112 of FIG. Be placed. An injection hole 21h extending from the outer peripheral surface of the main body 21B communicates with each of the inner peripheral surfaces of these different diameters. By arranging superconducting conductor layer 112 on the inner peripheral surface of different diameter and injecting a joining material such as solder from injection hole 21h, main body 21B can be joined to former 111 and superconducting conductor layer 112.

  A flange 21f is formed on the outer periphery of the main body 21B so as to protrude radially outward of the main body 21B. The outer diameter of the portion other than the flange portion 21f in the main body portion 21B is the same as the outer diameter of the large-diameter portion of the sealing tubular portion 21A, and is the same as the outer diameter of the sealing tubular portion 22A of the normal-conducting-side connecting portion 22 described later. Match. Therefore, as shown in the manufacturing method of the terminal structure 1 described later, after the conductor lead-out portion 2 is attached to the cable core 110, the normal-conduction-side heat-insulating container 5 can be easily inserted from the normal temperature end side of the conductor lead-out portion 2.

[[Normal conduction side connection]]
The normal conducting side connecting portion 22 is a member in which a bottomed cylindrical sealing tubular portion 22A and a plate-like metal fitting portion 22B extending from the outer bottom of the sealing tubular portion 22A are integrated with each other. Functions as a fitting to be connected. The inner diameter of the sealing tubular portion 22A is slightly larger (about 0.5 mm to 2 mm) than the outer diameter of the tubular portion 20. Therefore, the other end of the tubular portion 20 in the axial direction can be sealed by fitting the sealing tubular portion 22A to the other end of the tubular portion 20 in the axial direction. The joining between the tubular portion 20 and the sealing tubular portion 22A can be performed with solder or the like.

  The metal fitting part 22B is a rectangular plate-shaped member formed so as not to protrude from the outer peripheral contour of the sealing tubular part 22A when the conductor lead-out part 2 is viewed from the axial direction. The fitting part 22B is provided with a plurality of mounting holes 22h used for connection with the bus bar 200 (see FIG. 1). By mounting the mounting hole of the bus bar 200 and the mounting hole 22h of the metal part 22B coaxially and fixing the bolt 200b (see FIG. 1), the conductor lead-out part 2 and the normal conducting device can be electrically connected.

[Non-vacuum insulation]
As shown in FIGS. 1 and 2, the terminal structure 1 of the present embodiment includes a non-vacuum heat insulator 3 that covers a radially outer portion of the cylindrical portion 20 of the conductor lead-out portion 2. As described above, a non-vacuum heat-insulating structure (non-vacuum heat-insulating body 3) having a simpler structure than the vacuum heat-insulating structure may be used for the heat-insulating structure formed on the outer periphery of the cylindrical portion 20 of the conductor lead-out portion 2. it can. Since the non-vacuum heat insulator 3 having a simple structure is small and can be easily constructed, the terminal structure 1 of the superconducting device can be miniaturized, and its workability can be improved.

  The non-vacuum heat insulator 3 of the present example includes a case 30 surrounding the outside of the cylindrical portion 20 in the radial direction, and a resin 32 filled inside the case 30. The configuration of this example further includes a lid 31 that seals the open end of the case 30 on the normal conduction side, so that the case 30 can be easily filled with the resin 32. Unlike the present example, the non-vacuum heat insulator 3 can be formed by winding a heat insulating material such as a urethane sheet around the outer periphery of the tubular portion 20.

  The case 30 is provided with a resin filling port 30h communicating with the inside and outside of the case 30. Further, the lid 31 has a through hole 31h through which the sealing cylindrical portion 22A of the normal conducting side connection portion 22 of the conductor lead-out portion 2 is inserted. The case 30 and the lid 31 can be made of an appropriate metal or a resin having excellent strength.

  The resin 32 to be filled in the case 30 is not particularly limited as long as it has fluidity when filling the case 30 and has a property of being cured after filling the case 30. With the resin 32 having such a property, the outer periphery of the cylindrical portion 20 can be covered without a gap, so that the transfer of heat from the external environment to the cylindrical portion 20 can be effectively suppressed. Heat penetration can be suppressed. As the resin 32 filled in the case 30, for example, a thermosetting resin such as urethane foam or epoxy can be used. Further, in this example, since the inside of the tubular portion 20 is filled with the resin 32 via the through hole 20h of the tubular portion 20, it is possible to suppress the atmosphere from remaining inside the tubular portion 20. If there is residual air, the gas in the cylindrical portion 20 repeatedly evaporates and liquefies, thereby deteriorating the heat insulation performance and possibly causing stress to act on the peripheral members of the cylindrical portion 20 due to pressure fluctuations in the cylindrical portion 20. However, when the tubular portion 20 is filled with the resin 32, such a problem can be suppressed.

製造 Method for manufacturing terminal structure of superconducting device≫
The terminal structure 1 of the superconducting device according to the first embodiment can be constructed by, for example, a manufacturing method including the following steps.
・ Core processing process ・ Formation process of superconducting side heat insulation container ・ Connection process of conductor lead-out part ・ Process of forming normal conduction side heat insulation container ・ Placement process of insulator tube ・ Vacuum drawing process ・ Formation process of non-vacuum heat insulator

[Core processing step]
At the end of the superconducting cable 100, the cable core 110 having a predetermined length is taken out of the heat insulating tube 120, and the former is peeled off, and the former 111, the superconducting conductor layer 112, the electric insulating layer 113 and the like are exposed in order. In this example, after the reinforcing insulating layer 8 is formed in the vicinity of the heat insulating pipe 120 in the cable core 110, the shielding connection portion 80 is provided so as to extend from the shielding layer 114 to a part of the outer periphery of the reinforcing insulating layer 8.

[Process of forming superconducting-side heat insulating container]
The superconducting heat insulating container 6 is provided so as to cover the reinforcing insulating layer 8 of the cable core 110. Here, the inner tube 121 of the heat insulating tube 120 and the refrigerant tank 61 are joined by welding or the like, and the outer tube 122 of the heat insulating tube 120 and the vacuum tank 62 are joined by welding or the like. Then, the bottom plate portion 71 of the porcelain tube 7 is attached so as to close the opening end of the superconducting-side heat insulating container 6 on the normal conduction side. Note that the superconducting-side heat-insulating container 6 may be formed into a plurality of divided structures, and the superconducting-side heat-insulating container 6 may be formed after the normal-conducting-side heat-insulating container 5 described later is formed.

[Connecting process of conductor lead-out part]
The conductor lead-out section 2 is connected to the end of the cable core 110 projecting from the end of the superconducting-side heat insulating container 6. In connection, the end of the cable core 110 is inserted into the storage section 21s of the superconducting side connection section 21 provided in the conductor lead-out section 2, and solder is poured from each injection hole 21h (FIG. 3). By attaching an elastic fitting or the like to the outer periphery of the former 111, the former 111 is press-fitted into the storage part 21s, and the former 111 is firmly fixed to the storage part 21s.

[Process of Forming Normal-Conduction-Side Insulated Container]
In this example, an integrated member in which the insulating cylinder 4 is integrated with the outer periphery of the normal-conduction-side heat-insulating container 5 including the refrigerant tank 51 and the vacuum tank 52 is manufactured in a factory or the like. The integrated member is fitted to the outside of the cable core 110 from the conductor lead-out portion 2 side, and the fixing portion 40 provided on the outer periphery of the insulating cylinder 4 is fixed to the bottom plate portion 71. As shown in FIG. 2, a step formed on the inner peripheral surface of the normal temperature side end of the refrigerant tank 51 is formed by a flange portion 21 f formed on the outer peripheral surface of the normal conducting side connection portion 22 of the conductor lead-out portion 2 (FIG. 3). See).

[Positioning process of insulator tube]
The insulator tube 7 is covered so as to cover the room temperature side region of the insulating cylinder 4. In this example, the main body 70 and the upper plate 72 are fitted into the outside of the normal-conduction-side heat-insulating container 5 from the conductor lead-out portion 2 side, and the three members 70, 71, 72 are connected. At this time, the normal-conduction-side heat-insulating container 5 protrudes from the upper plate 72. The introduction of the insulating fluid into the insulator tube 7 can be performed at an appropriate time.

[Evacuation process]
Using the vacuum ports 50p and 60p, the normal-conduction-side heat-insulating container 5 and the superconducting-side heat-insulating container 6 are evacuated. The heat insulating tube 120 can be evacuated in advance at a factory or the like. Using the vacuum port 100p provided in the heat insulating pipe 120, the vacuum state can be adjusted even at the construction site or after the installation. With respect to both the heat insulating containers 5 and 6, the vacuum state can be adjusted even after the installation using the vacuum ports 50p and 60p.

[Process of forming non-vacuum heat insulator]
As shown in FIG. 2, a cylindrical case 30 having both open ends is fitted to the outside of the cylindrical portion 20 from the distal end side of the conductor lead portion 2, and the case 30 is fixed to the upper plate portion 72. Next, the lid 31 having a through hole 31h in the center is fitted from the front end side of the conductor lead-out portion 2 to seal the open end of the case 30 on the room temperature side. Then, the resin 32 is filled through the resin filling port 30h of the case 30. The resin 32 filled in the case 30 also fills the inside of the tubular portion 20 through a through hole 20 h provided in the tubular portion 20 of the conductor lead-out portion 2. When the filling of the resin 32 is completed, the resin 32 is cured to complete the non-vacuum heat insulator 3. After the formation of the non-vacuum heat insulator 3, the upper shield 75 is provided on the outer periphery of the case 30.

  When the above steps are completed, the superconducting cable line can be operated by introducing the refrigerant 130 and maintaining the superconducting conductor layer 112 in the superconducting state, so that power can be exchanged with the normal conducting power equipment.

≪Effect≫
The terminal structure 1 of the superconducting device according to the first embodiment can suppress the conduction of heat to the superconducting cable 100 via the conductor lead-out portion 2 by providing the tubular portion 20 in the conductor lead-out portion 2. In addition, by providing the conductor lead-out portion 2 having the cylindrical portion 20, the heat insulating structure that insulates the cylindrical portion 20 from the external environment can be a non-vacuum heat insulator 3 having a simple structure. The terminal structure 1 can be miniaturized by the non-vacuum heat insulator 3 having a simple structure, and its workability can be improved. In particular, since a large number of terminal structures 1 are formed in the power transmission network using the superconducting cable 100, the improvement of the workability of each terminal structure 1 greatly contributes to the improvement of the workability of the entire power transmission network.

  Also, the non-vacuum heat insulator 3 having a simple structure can be easily disassembled. For example, even if the non-vacuum heat insulator 3 is disassembled during the maintenance of the terminal structure 1, the trouble of disassembly and the trouble of rebuilding after the maintenance are much easier than the vacuum heat insulation structure.

<Embodiment 2>
In the first embodiment, the inside of the cylindrical portion 20 of the conductor lead-out portion 2 is also filled with the resin 32. On the other hand, in a second embodiment, a configuration in which the refrigerant 131 is circulated inside the tubular portion 20 using the refrigerant circulating mechanism 9 will be described with reference to FIG. FIG. 5 is a partial longitudinal sectional view of the vicinity of the non-vacuum heat insulator 3 in the terminal structure 1, and the same components as those of the first embodiment shown in FIG. 2 are denoted by the same reference numerals.

  The conductor lead-out portion 2 of the present example includes two refrigerant ports 20p in the tubular portion 20. The refrigerant introduction pipe 91 of the refrigerant distribution mechanism 9 is connected to one refrigerant port 20p, and the refrigerant discharge pipe 99 of the refrigerant distribution mechanism 9 is connected to the other refrigerant port 20p. The refrigerant 131 circulated through the tubular portion 20 by the refrigerant circulating mechanism 9 may be a refrigerant of the same system as the refrigerant 130 that cools the superconducting cable 100 or a refrigerant of a different system. When the refrigerant 131 of the refrigerant distribution mechanism 9 is different from the refrigerant 130 of the superconducting cable 100, the refrigerant 131 may be a refrigerant having a higher temperature than the refrigerant 130. For example, the refrigerant 131 may be a gas-liquid mixed refrigerant. Here, since the pipes 91 and 99 are connected to the high-potential conductor lead-out portion 2, it is necessary to insulate the pipes 91 and 99 in the middle with an insulating joint or the like.

  According to the configuration of the second embodiment, it is possible to remove the heat generated in the normal-conducting-side connecting portion 22 and the cylindrical portion 20 generated during the load, and it is easy to suppress the temperature of the superconducting cable 100 from increasing. Here, in the terminal structure 1 of the superconducting device according to the embodiment, since the heat insulating structure covering the outer periphery of the tubular portion 20 is the non-vacuum heat insulator 3, the refrigerant introduction pipe 91 and the refrigerant discharge pipe constituting the refrigerant distribution mechanism 9 are provided. 99 is easy to arrange.

<Other embodiments>
Different from the first and second embodiments, a gas such as the atmosphere may be sealed inside the tubular portion 20 of the conductor lead-out portion 2. For example, if the diameter of the through-hole 20h in the tubular portion 20 of the first embodiment is reduced, it is possible to suppress the resin from entering the inside of the tubular portion 20. If the inside of the tubular portion 20 is air, there is no need to fill the resin 32 (FIG. 2) as in the first embodiment or to circulate the refrigerant 131 (FIG. 5) as in the second embodiment. 1 is easier to construct.

DESCRIPTION OF SYMBOLS 1 Terminal structure of superconducting device 11 Refrigerant introduction pipe 19 Refrigerant discharge pipe 2 Conductor lead-out part 20 Cylindrical part 20h Through hole 20p Refrigerant port 21 Superconducting side connection part 21A Sealing cylinder part 21B Main part 21c Refrigerant flow path 21f Flange part 21h Injection Hole 21p Fastening hole 21s Storage part 22 Normal conduction side connection part 22A Sealing cylinder part 22B Metal fitting part 22h Mounting hole 3 Non-vacuum heat insulator 30 Case 31 Cover 32 Resin 30h Resin filling port 31h Through hole 4 Insulation cylinder 40 Fixed part 5 Normal Conducting-side heat-insulating container 51 Refrigerant tank 52 Vacuum tank 6 Superconducting-side heat-insulating container 61 Refrigerant tank 62 Vacuum tank 7 Insulator tube 70 Main body 71 Bottom plate 72 Upper plate 75 Upper shield 8 Reinforcement insulating layer 80 Shield connection 9 Refrigerant circulation mechanism 91 Refrigerant 91 Inlet pipe 99 Refrigerant discharge pipe 50p, 60p, 100p Vacuum port 100 Superconducting cable 110 cable Lucor 111 Former 112 Superconducting conductor layer 113 Electrical insulating layer 114 Shielding layer 115 Protective layer 120 Heat insulating tube 121 Inner tube 122 Outer tube 123 Heat insulating material 124 Anticorrosion layer 130, 131 Refrigerant 200 Busbar 200b Volt

Claims (6)

A terminal structure of a superconducting device including a normal-conduction conductor lead-out portion electrically connected to an end of a superconducting conductor of the superconducting device,
The conductor lead-out portion,
A tubular portion,
A superconducting-side connecting portion that seals one end side of the cylindrical portion in the axial direction and has a storage portion that stores an end of the superconducting conductor,
Along with sealing the other end of the cylindrical portion in the axial direction, a normal-conducting-side connection portion serving as a bracket connected to a normal-conduction device,
Furthermore, a terminal structure of a superconducting device including a non-vacuum heat insulator covering a radially outer peripheral surface of the cylindrical portion.   2. The terminal structure for a superconducting device according to claim 1, wherein the non-vacuum heat insulator includes a case surrounding a radially outer side of the cylindrical portion, and a resin filled inside the case. 3. The cylindrical portion includes a through hole penetrating the inside and outside thereof,
The terminal structure for a superconducting device according to claim 2, wherein the resin is also filled inside the cylindrical portion through the through hole.   The terminal structure of a superconducting device according to claim 1, further comprising a refrigerant distribution mechanism that distributes a refrigerant inside the cylindrical portion.   The terminal structure of a superconducting device according to any one of claims 1 to 4, wherein the superconducting device is a superconducting cable including a cable core including the superconducting conductor and a heat insulating tube that stores the cable core. . An insulating tube through which a part of the cable core is inserted,
A normal-conduction-side heat-insulating container that is arranged on the side of the conductor lead-out portion of the insulating cylinder and houses the normal-conduction-side connection portion together with an end of the cable core,
The terminal structure of a superconducting device according to claim 5, further comprising: a superconducting-side heat-insulating container disposed on the side of the superconducting cable in the insulating tube and connected to the heat-insulating pipe of the superconducting cable.

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